The task to which this project is directed is a comprehensive understanding of inherited disorders of human galactose metabolism and inherited derangements of cellular transport. The underlying approach is the application of biochemical techniques for the delineation of basic alterations of cellular function resulting from altered genetic expression. The research will be conducted not only in patients and appropriate animal models but also in cellular and subcellular systems. Aspects of galactose metabolism to be studied are 1) the nature of galactose toxicity in the newborn rat and chick, 2) the regulation of galactose metabolism based on enzyme kinetics and developmental patterns of enzyme activivies as well as hormonal and dietary manipulations, 3) galactose utilization and its control in the perfused rat liver and 4) quantitation and control of galactose metabolism in patients with galactosemia. Also certain aspects of cellular transport, especially sugar and amino acid transport in kidney cortex slices are under investigation.